Field
Aspects of embodiments of the present invention relate to a secondary battery.
Related Art
In general, unlike primary batteries, which are not chargeable, secondary batteries are chargeable and dischargeable. The secondary batteries, in particular, small size batteries, are widely used in a variety, of, high-tech electronic devices such as cellular phones, notebook computers, camcorders, and the like, and bulk size (e.g., large size) batteries are used as the power source for motor drive, such as in electric vehicles or hybrid electric vehicles. The secondary battery is generally constructed to include an electrode assembly inside a case and electrode terminals connected through a collector plate welded to the electrode assembly. However, in some secondary batteries it is difficult to check welding quality from the outside and therefore welding efficiency may deteriorate.